A horizontal bar chart displays the population of the top 20 countries in 2010, with countries listed on the y-axis and population values on the x-axis. Built with React and D3 v5, the visualization uses `d3.scaleBand` for the categorical axis, `d3.scaleLinear` for the numeric axis, and `d3.format` to abbreviate large numbers. Data is fetched from a CSV file using `d3.csv`. Each bar includes a tooltip showing the formatted population value.